Fuse plug



March 18, 1930.

E. F. PELLETIER ET Al. 1,751,055

FUSE PLUG Filed Oct. 22, 1928 E www 1 @6%753/4 a/c/ @my d 7 PatentedMar. 18, 1930 UNITED STATES PATENT OFFICE ECMIMET F. PELLETIER, OF ST.JOSEPH, AND WALTER E. BANDLOW, 0F BENTON y HARBOR, MICHIGAN FUSE PLUGApplication led Bctoher 22, 1928. Serial No. 314,266.

given on the outer side of the plug wheneverv fusing occurs, and toprovide a construction which is very simple and easily produced.

An embodiment of the invention is shown in the accompanying drawings, inwhich Figure 1 is a sectional view through the fuse plug.

Figure 2 is a transverse, sectional view on the line 2 2 of Figure 1.

Figure 3 is a view from the' upper side of the plug with the capremoved, and with parts broken away.

Figure 4 is a view from the under side of the plug with the shellremoved.

Referring to the drawings, it will be seen that the fuse plug comprisesan outer shell 1 which may be screw-threaded, if desired, and 30. whichis provided with a metal ferrule or covering 2. This covering isconnected internally to the contact strip 3. A central contact member 4is provided in the form of a rivet and is connected internally of theshell with the contact strip 5. The contact strips 3 and 5 have theirupper ends turned over the upper end of the shell and are adapted toengage contact members 6 and 7 carried by the re- Within the ring 8 theremovable sleeve is adapted to clamp the ends of the fusible strip 10 incontact with the metal members 6 and 7, such-members contacting with theterminal members or contact strips 3 and 5.

The shell is screw-threaded adjacent its upper end and is adapted toreceive the removable screw-threaded cap 11 by means of which the partsare clamped together.

Further, it is to be noted that a springpressed plunger 12 is slidablycarried by the movable ring 8 when the plug is assembled.:

sleeve 9. Preferably the sleeve 9 is provided with a flange 13 whichtits slidably within al1V annular recess formed in the plunger 12. Theplunger 12 is also provided with a pin 14 which projects through theouter cap 11 so 55 that when the fusible member 10 melts, the pin ismoved inwardly and thus the condition of the fuse is readily indicated.The spring for urging the plunger 12 downwardly is indicated at 15 andis within a recess formed in 60 the sleeve 9, as shown in Figure 1.

It is preferable to provide a constricted portion 10 for the fuse strip10, as shown in Figure 4, such constricted portion being locatedcentrally of the outer end of the c5 plunger.

In using the device, it is apparent that when the fuse blows, the springwill project the plunger downwardly between the ends of the fusiblestrip and that the pin 14 will move 70 ifnwardly, thus indicating thecondition of the use.

The fuse is readily renewable as the cap may be unscrewed and the sleeve9 separated from the ring 8. Thereafter a new fuse strip is positioned,as indicated in Figure l, and the sleeve 9 is again inserted in thering, thus binding the fuse strip in contact with the contact members 6and 7. When the cap is again screwed down, the contact members 6 and 7So are forced into engagement with the terminal members or strips 3 and5, and the plug is again ready for use.

It will be seen that a very simple type of device has been provided bythis invention, S5 which may be readily and cheaply manufactured, whichhas a comparatively small number of parts, which permits ready renewalof the fuse strip, and which is easy to operate.

Although the invention has been described in considerable detail, suchdescription is intended as illustrative rather than limiting as theinvention may be variously embodied and as the scope of such inventionis to be determined as claimed.

We claim 1. A fuse plug comprising a casing, a ring carried by saidcasing, a sleeve fitting within said ring and adapted to clamp a fusestrip between itself and ring, a plunger springpressed downwardly andcarried by sald sleeve, and a fuse strip surrounding said plunger andholding it inwardly.

2. A renewable indicating fuse plug comprising a shell provided withterminals, a ring and a sleeve adapted to hold between them a renewablefuse strip, a plunger carried by said sleeve and spring-pressed inwardlyand restrained by said fuse strip, a cap holding said sleeve and ring inplace and screwed upon said shell.

3. A renewable indicating fuse plug comprising a shell provided withterminals, a ring and a sleeve adapted to hold between them a` renewablefuse strip, a plunger carried by said sleeve and spring-pressed inwardlyand restrained by said fuse strip, a cap holding said sleeve and ring inplace and screwed upon said shell, said cap having a central apertureand a. pin carried by said plunger and projecting through the centralapertures of said cap.

In testimony that We claim the foregoing We have hereunto set our handsat. St. Joseph, in the county .of Berrien and State of Michi- Gan.

a EMMET F. PELLETIER. WALTER E. BANDLOV.

